> On Oct 2, 2019, at 08:07, Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote: > > [+cc Alan, Mathias, Rafael, Lukas] > > On Mon, Sep 02, 2019 at 10:52:52PM +0800, Kai-Heng Feng wrote: >> There's an xHCI device that doesn't wake when a USB 2.0 device gets >> plugged to its USB 3.0 port. The driver's own runtime suspend callback >> was called, PME# signaling was enabled, but it stays at PCI D0: >> >> 00:10.0 USB controller [0c03]: Advanced Micro Devices, Inc. [AMD] FCH USB XHCI Controller [1022:7914] (rev 20) (prog-if 30 [XHCI]) >> Subsystem: Dell FCH USB XHCI Controller [1028:087e] >> Control: I/O- Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ >> Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- >> Interrupt: pin A routed to IRQ 18 >> Region 0: Memory at f0b68000 (64-bit, non-prefetchable) [size=8K] >> Capabilities: [50] Power Management version 3 >> Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0+,D1-,D2-,D3hot+,D3cold+) >> Status: D0 NoSoftRst+ PME-Enable+ DSel=0 DScale=0 PME- >> >> A PCI device can be runtime suspended while still stays at D0 when it >> supports D0 PME# and its ACPI _S0W method reports D0. Though plugging >> USB 3.0 devices can wakeup the xHCI, it doesn't respond to USB 2.0 >> devices. > > I don't think _S0W and runtime suspend are relevant here. What *is* > relevant is that the device advertises that it can generate PME from > D0, and it apparently does not do so. Yes that's the case. It doesn't generate PME when USB2.0 or USB1.1 device gets plugged. > > Table 10 in the xHCI spec r1.0, sec 4.15.2.3, says the xHC should > assert PME# if enabled and the port's WCE bit is set. Did you ever > confirm that WCE is set? How do I check WCE when xHCI is suspended? If I want to read WCE then I have the resume the device, but after resuming all USB devices get enumerated, and checking WCE doesn't matter anymore. > > I assume WCE *is* set because plugging in a USB3 device *does* > generate a PME#, and I don't see anything in Table 10 that says it > would work for USB3 but not USB2. It should work on all USB speeds, but it didn't. That's why the OEM/ODM use the _S0W workaround on Windows. Kai-Heng > >> So let's disable D0 PME capability on this device to avoid the issue. >> >> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203673 >> Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx> >> --- >> arch/x86/pci/fixup.c | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/arch/x86/pci/fixup.c b/arch/x86/pci/fixup.c >> index 527e69b12002..0851a05d092f 100644 >> --- a/arch/x86/pci/fixup.c >> +++ b/arch/x86/pci/fixup.c >> @@ -588,6 +588,17 @@ static void pci_fixup_amd_ehci_pme(struct pci_dev *dev) >> } >> DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, 0x7808, pci_fixup_amd_ehci_pme); >> >> +/* >> + * Device [1022:7914] >> + * D0 PME# doesn't get asserted when plugging USB 2.0 device. >> + */ >> +static void pci_fixup_amd_fch_xhci_pme(struct pci_dev *dev) >> +{ >> + dev_info(&dev->dev, "PME# does not work under D0, disabling it\n"); > > Use pci_info() as in the rest of the file. > >> + dev->pme_support &= ~(PCI_PM_CAP_PME_D0 >> PCI_PM_CAP_PME_SHIFT); >> +} >> +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD, 0x7914, pci_fixup_amd_fch_xhci_pme); >> + >> /* >> * Apple MacBook Pro: Avoid [mem 0x7fa00000-0x7fbfffff] >> * >> -- >> 2.17.1
